/******************************************************************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *****************************************************************************/

#include "qwt_text_label.h"
#include "qwt_text.h"
#include "qwt_painter.h"
#include "qwt_math.h"

#include <qstyle.h>
#include <qstyleoption.h>
#include <qpainter.h>
#include <qevent.h>
#include <qmargins.h>

class QwtTextLabel::PrivateData
{
public:
  PrivateData()
    : indent(4)
    , margin(0)
  {
  }

  int indent;
  int margin;
  QwtText text;
};

/*!
   Constructs an empty label.
   \param parent Parent widget
 */
QwtTextLabel::QwtTextLabel(QWidget *parent)
  : QFrame(parent)
{
  init();
}

/*!
   Constructs a label that displays the text, text
   \param parent Parent widget
   \param text Text
 */
QwtTextLabel::QwtTextLabel(const QwtText &text, QWidget *parent)
  : QFrame(parent)
{
  init();
  m_data->text = text;
}

//! Destructor
QwtTextLabel::~QwtTextLabel()
{
  delete m_data;
}

void QwtTextLabel::init()
{
  m_data = new PrivateData();
  setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
}

/*!
   Interface for the designer plugin - does the same as setText()
   \sa plainText()
 */
void QwtTextLabel::setPlainText(const QString &text)
{
  setText(QwtText(text));
}

/*!
   Interface for the designer plugin

   \return Text as plain text
   \sa setPlainText(), text()
 */
QString QwtTextLabel::plainText() const
{
  return m_data->text.text();
}

/*!
   Change the label's text, keeping all other QwtText attributes
   \param text New text
   \param textFormat Format of text

   \sa QwtText
 */
void QwtTextLabel::setText(const QString &text, QwtText::TextFormat textFormat)
{
  m_data->text.setText(text, textFormat);

  update();
  updateGeometry();
}

/*!
   Change the label's text
   \param text New text
 */
void QwtTextLabel::setText(const QwtText &text)
{
  m_data->text = text;

  update();
  updateGeometry();
}

//! Return the text
const QwtText &QwtTextLabel::text() const
{
  return m_data->text;
}

//! Clear the text and all QwtText attributes
void QwtTextLabel::clear()
{
  m_data->text = QwtText();

  update();
  updateGeometry();
}

//! Return label's text indent in pixels
int QwtTextLabel::indent() const
{
  return m_data->indent;
}

/*!
   Set label's text indent in pixels
   \param indent Indentation in pixels
 */
void QwtTextLabel::setIndent(int indent)
{
  if (indent < 0)
    indent = 0;

  m_data->indent = indent;

  update();
  updateGeometry();
}

//! Return label's text margin in pixels
int QwtTextLabel::margin() const
{
  return m_data->margin;
}

/*!
   Set label's margin in pixels
   \param margin Margin in pixels
 */
void QwtTextLabel::setMargin(int margin)
{
  m_data->margin = margin;

  update();
  updateGeometry();
}

//! Return a size hint
QSize QwtTextLabel::sizeHint() const
{
  return minimumSizeHint();
}

//! Return a minimum size hint
QSize QwtTextLabel::minimumSizeHint() const
{
  QSizeF sz = m_data->text.textSize(font());

  const QMargins m = contentsMargins();

  int mw = m.left() + m.right() + 2 * m_data->margin;
  int mh = m.top() + m.bottom() + 2 * m_data->margin;

  int indent = m_data->indent;
  if (indent <= 0)
    indent = defaultIndent();

  if (indent > 0)
  {
    const int align = m_data->text.renderFlags();
    if (align & Qt::AlignLeft || align & Qt::AlignRight)
      mw += m_data->indent;
    else if (align & Qt::AlignTop || align & Qt::AlignBottom)
      mh += m_data->indent;
  }

  sz += QSizeF(mw, mh);

  return QSize(qwtCeil(sz.width()), qwtCeil(sz.height()));
}

/*!
   \param width Width
   \return Preferred height for this widget, given the width.
 */
int QwtTextLabel::heightForWidth(int width) const
{
  const int renderFlags = m_data->text.renderFlags();

  int indent = m_data->indent;
  if (indent <= 0)
    indent = defaultIndent();

  const QMargins m = contentsMargins();

  width -= m.left() + m.right() - 2 * m_data->margin;
  if (renderFlags & Qt::AlignLeft || renderFlags & Qt::AlignRight)
    width -= indent;

  int height = qwtCeil(m_data->text.heightForWidth(width, font()));
  if ((renderFlags & Qt::AlignTop) || (renderFlags & Qt::AlignBottom))
    height += indent;

  height += m.top() + m.bottom() + 2 * m_data->margin;

  return height;
}

/*!
   Qt paint event
   \param event Paint event
 */
void QwtTextLabel::paintEvent(QPaintEvent *event)
{
  QPainter painter(this);
  painter.setClipRegion(event->region());

  QStyleOption opt;
  opt.initFrom(this);
  style()->drawPrimitive(QStyle::PE_Widget, &opt, &painter, this);

  if (!contentsRect().contains(event->rect()))
  {
    painter.setClipRegion(event->region() & frameRect());
    drawFrame(&painter);
  }

  painter.setClipRegion(event->region() & contentsRect());

  drawContents(&painter);
}

//! Redraw the text and focus indicator
void QwtTextLabel::drawContents(QPainter *painter)
{
  const QRect r = textRect();
  if (r.isEmpty())
    return;

  painter->setFont(font());
  painter->setPen(palette().color(QPalette::Active, QPalette::Text));

  drawText(painter, QRectF(r));

  if (hasFocus())
  {
    const int m = 2;

    QRect focusRect = contentsRect().adjusted(m, m, -m + 1, -m + 1);

    QwtPainter::drawFocusRect(painter, this, focusRect);
  }
}

//! Redraw the text
void QwtTextLabel::drawText(QPainter *painter, const QRectF &textRect)
{
  m_data->text.draw(painter, textRect);
}

/*!
   Calculate geometry for the text in widget coordinates
   \return Geometry for the text
 */
QRect QwtTextLabel::textRect() const
{
  QRect r = contentsRect();

  if (!r.isEmpty() && m_data->margin > 0)
  {
    const int m = m_data->margin;
    r.adjust(m, m, -m, -m);
  }

  if (!r.isEmpty())
  {
    int indent = m_data->indent;
    if (indent <= 0)
      indent = defaultIndent();

    if (indent > 0)
    {
      const int renderFlags = m_data->text.renderFlags();

      if (renderFlags & Qt::AlignLeft)
      {
        r.setX(r.x() + indent);
      }
      else if (renderFlags & Qt::AlignRight)
      {
        r.setWidth(r.width() - indent);
      }
      else if (renderFlags & Qt::AlignTop)
      {
        r.setY(r.y() + indent);
      }
      else if (renderFlags & Qt::AlignBottom)
      {
        r.setHeight(r.height() - indent);
      }
    }
  }

  return r;
}

int QwtTextLabel::defaultIndent() const
{
  if (frameWidth() <= 0)
    return 0;

  QFont fnt;
  if (m_data->text.testPaintAttribute(QwtText::PaintUsingTextFont))
    fnt = m_data->text.font();
  else
    fnt = font();

  return QwtPainter::horizontalAdvance(QFontMetrics(fnt), 'x') / 2;
}

#if QWT_MOC_INCLUDE
#  include "moc_qwt_text_label.cpp"
#endif
